The new and distinct variety of grapevine originated from a hand-pollinated cross of Arkansas Selection 1258 (non-patented)xc3x97Arkansas Selection 1672 (non-patented) made in 1981 at the Arkansas Agricultural Experiment Station Fruit Substation at Clarksville, Ark. Arkansas selection 1258 is a seeded, red-fruited grape with large, round, slipskin (pulp does not adhere to the flesh) berries with a foxy flavor that ripen approximately one week after the instant variety. Arkansas selection 1672 is a seedless, green or white-fruited grape with large, oval, non-slipskin (pulp adheres to the flesh) berries with a muscat flavor, that ripen approximately one week after the instant variety. Both of the parents of the instant cultivar are hybrids of the grape genus and species Vitis labrusca L. and Vitis vinfera L. Thus the instant cultivar is also of this two-species genetic background. The seeds resulting from this controlled hybridization were germinated in a greenhouse during the winter of 1981-82. Resulting seedlings were planted in the spring of 1982 in a vineyard on the Arkansas Agricutural Experiment Station at Clarksville, Ark. The seedlings fruited in the summer of 1984 and one, designated Ark. 1985, was selected for its large seedless fruits, unique muscat flavor, and good fruit quality.
During 1984, the original plant selection was propagated asexually at Clarksville, Arkansas by rooting hardwood cuttings and a test planting of three vines was established. Subsequently, larger test plantings have been established with asexually multiplied vines at two additional locations in Ark. and on state agricultural experiment stations in Athens, Ga. USA, West Lafayette, Ind. USA, and Pelotas, Rio Grande do Sul, Brazil. In all propagations hardwood cuttings were used and the instant cultivar roots readily from hardwood cuttings. All propagules (resulting plants) of the instant cutivar have been observed to be true to type in that during all asexual multiplication, the vegetative and fruit characteristics of the original plant have been maintained. All vines planted from hardwood cutting propagation fruited in the third season of growth in the vineyard after planting.
Test plantings over a wide geographic area have shown this new variety to be widely adapted to differing soil and climatic conditions. It has shown moderate winter hardiness during cold winters, being more hardy than the cultivars xe2x80x98Einset Seedlessxe2x80x99 (U.S. Plant Pat. No. 6,160), xe2x80x98Canadicexe2x80x99 (non-patented), xe2x80x98Himrodxe2x80x99 (non-patented), xe2x80x98Saturnxe2x80x99 (U.S. Plant Pat. No. 6,703), xe2x80x98Vanessa Seedlessxe2x80x99 (non-patented), and xe2x80x98Venusxe2x80x99 (non-patented), but less hardy than the cultivars xe2x80x98Marsxe2x80x99 (U.S. Plant Pat. No. 5,680) and xe2x80x98Reliancexe2x80x99 (U.S. Plant Pat. No. 5,174). It is not as sensitive to 2,4-D herbicide injury as the cultivars xe2x80x98Marsxe2x80x99, xe2x80x98Sunbeltxe2x80x99 (U.S. Plant Pat. No. 8,511), and xe2x80x98Remaily Seedlessxe2x80x99 (non-patented).
Vines of the new variety have medium vigor, with a procumbent growth habit characteristic of Vitis labrusca (a comparative species). Vigor, as reflected in dormant pruning weights measured on mature vines, indicated that the instant cultivar was less vigorous than xe2x80x98Marsxe2x80x99, and near comparable in vigor to that of xe2x80x98Venusxe2x80x99. Also, vine size as determined on vines growing on a Four-Arm Kniffin trellis with the top wire of this trellis placed at a height of 4 ft. 10 in., indicated a vine height of 5 ft. 5 in. an a vine spread of 2 ft. 6 in. It has produced well as own-rooted plants in all locations tested.
The new variety is moderately resistant to most common fungus diseases of grapevines. Under normal chemical disease control programs, the vines and fruit have demonstrated good freedom from black rot (Guignardia bidwellii (Ell.) V. and R.), anthrancnose (Elsinoe ampelina (d. By.) Sher), and powdery mildew (Uncinula necator Burr.), but it is susceptible to downy mildew (Plasmopora viticola Berl. and Tomi.) which is controllable by the use of available fungicides. The fruit has shown no inclination to split following rains.
The new variety ripens its fruit in early midseason, five days later than the early maturing xe2x80x98Venusxe2x80x99 cultivar but five and twelve days earlier than xe2x80x98Reliancexe2x80x99 and xe2x80x98Marsxe2x80x99, respectively. The average ripening date is July 24 in central Arkansas. The fruit quality is maintained well on the vine after maturity. Fruit of sound quality for marketing is maintained for up to two weeks on the vines after initial maturity is reached. Berries adhere well to the fruit pedicel and do not shatter from the clusters during this time.
The fruit is reddish blue in color at early maturity and becomes completely blue when fully mature. It is evenly colored within the cluster. The fruit shape is oval to slightly oblong. Fruit skins are medium thick and adhere to the flesh. The berries are large in size (ca. 5.5 g). The flavor is a mild muscat, and has been consistently rated high. Soluble solids concentration of the juice at fruit maturity average 19.8% with pH of 3.50. The fruit is of the stenospermocarpic type of seedlessness and contains small, soft vestigial seed traces that are not noticeable when eaten. The berries are large in size for a seedless grape, averaging twice the size of the xe2x80x98Marsxe2x80x99 and xe2x80x98Reliancexe2x80x99 cultivars.
Fruit clusters, borne usually two per shoot, are medium in size (ca. 257 g), well-filled, but not overly tight. Fruit cluster peduncles are medium-long and easy to remove from the supporting shoots during harvest.
The new variety has been named the xe2x80x98JUPITERxe2x80x99 cultivar.